Hand held flexible mount leak detector

ABSTRACT

A hand held refrigeration leak detector provides single hand operation for a user while holding the main body of the detector. The flexible stalk is coupled to the main body and to a head containing an LED light source which provides spectral emissions in the UV to blue range.

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. 119(e) ofU.S. Provisional Application Serial No. 60/304,928, entitled FlexibleMount Leak Detection, filed on Jul. 12, 2001.

FIELD OF INVENTION

[0002] The present invention relates generally to a hand held tool fordetecting leaks in pressurized air conditioning systems.

BACKGROUND OF THE INVENTION

[0003] A frequent problem with pressurized refrigeration systems is asmall refrigerant leak at a fitting, joint, or in a hose. One method fordetecting the leak from the pressurized refrigeration system is toinject a fluorescent dye into the pressurized refrigeration system andthen to use a UV/Blue (Ultra-Violet/Blue) light source to detect the dyeand thus locate the leak site. Alternatively, the leak may be detectedby using a halogen gas sensor (detector). Typically, a refrigerant leakis very difficult to detect and pinpoint when using only gas detector orwhen using only UV/Blue light. The nature of the refrigerant leakdetermines which method works best, thus the best method to use may notbe known in advance. Traditional UV/Blue light sources are large and gethot under normal operating conditions. In a confined environment, suchas an automobile, the use of a traditional UV/Blue light source can be ahazard in the confined quarters as well as difficult or impossible touse for fittings and hoses that are not easily accessible.

[0004] Therefore there is a need for a hand held leak detector which canbe safely and easily operated in the confined quarters.

SUMMARY OF THE INVENTION

[0005] The present invention is a hand held refrigeration leak detectorwhich provides single hand operation for a user while holding the mainbody of the detector. The flexible stalk is coupled to the main body andto a head containing an LED light source which provides spectralemissions in the UV to blue range.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] A more complete understanding of the present invention may beobtained from consideration of the following description in conjunctionwith the drawings in which:

[0007]FIG. 1 is a schematic view of a pressurized air conditioningrefrigeration system, which utilizes the present invention;

[0008]FIG. 2 is a high level stylized drawing of the hand held flexiblemount leak detector; and

[0009]FIGS. 3a, 3 b, 3 c and 3 d are exemplary sensor probe headembodiments.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0010] The present invention is a hand held flexible mount leak detectorfor detecting leaks in pressurized air conditioning systems. Referringto FIG. 1 there is shown a simplified schematic view of a typicalpressurized air conditioning refrigeration system, which utilizes thepresent invention, hand held flexible mount leak detector. Essentially,the pressurized air conditioning refrigeration system comprises acompressor 102, connective conduits 104, 106, 108, 110 and 112, anevaporator 114, an expansion valve 116, a condenser 118, and an accessfitting 120, which form a closed loop. The compressor 102 is coupled bya first connective conduit 104 to the evaporator 114. A secondconnective conduit 106 couples the evaporator 114 to the expansion valve116. A third connective conduit 108 couples the expansion valve 116 tothe condenser 118. A fourth connective conduit 110 couples the condenser118 to the access fitting 120. A fifth connective conduit 112 couplesthe access fitting 120 to the compressor, thus completing the closedloop. The access fitting 120 has a valve 122 with removable core (notshown). The access fitting is used to fill, purge and drain the closedsystem with refrigerant, as well as to add lubricants and dyes to thesystem.

[0011] The present invention, hand held flexible mount leak detector,addresses the need by the refrigeration industry for a small leakdetector with remote sensing that can be operated and positioned withone hand and combines a halogen gas sensor and UV/Blue light source toilluminate fluorescence dye. One method for detecting the refrigerantleak from the pressurized refrigeration system is to inject afluorescent dye into the pressurized refrigeration system and then touse a UV/Blue light source to detect the dye and thus locate the leaksite. Alternatively, the leak may be detected by using a halogen gassensor (detector). The refrigerant leak is very difficult to detect andpinpoint when using only gas detector or when using only UV/Blue light.The nature of the refrigerant leak determines which method works best,thus the best method to use may not be known in advance. TraditionalUV/Blue light sources are large and get hot under normal operatingconditions. In a confined environment, such as an automobile, the use ofa traditional UV/Blue light source can be a hazard in the confinedquarters.

[0012] Due to space limitations it has not-been possible to locate a gassensor and traditional UV/Blue light on a small common probe.Furthermore, a traditional UV/Blue source is large and get hot undernormal operating conditions, which is poses a fire hazard in confinedquarters, such as that of an automobile engine compartment or thepassenger compartment area behind the dash board. The ability to use asmall hand held flexible mount probe enables the rapid pinpointing ofthe refrigerant leak. By utilizing a high power UV/Blue light source,such as a Light Emitting Diode (LED) having a typical emitting sourcefrom UV to blue, a small hand held flexible mount probe can beconstructed and used to access leak sites with limited access (such asan automobile engine compartments and the passenger compartment areabehind the dash board). The emission of the UV/Blue LED is selected tocorrespond to a particular fluorescent dye's properties. A combinationof a blue and a UV LED or a single high energy blue LED or UV LED can beutilized. By utilizing a combination of LEDs having various emissionspectra, the hand held flexible mount leak detector will operate with avariety of fluorescent dyes. The fluorescent dye is inserted into therefrigeration system and will mark the area of the leak when it iscarried out of the leak with a small amount of lubricant, provided theleak is of sufficient size.

[0013] By combining a halogen gas sensor and UV/Blue light source in thepresent invention hand held flexible mount leak detector, a refrigerantleak is more rapidly detected and pin pointed (located) that by using ahalogen gas sensor or UV/Blue light source alone than by the use ofeither detector alone. This combination is only possible because of theefficient (low heat) illumination and small size provided by the UV/BlueLED light source. A variety of halogen gas sensors may be used, such asthe photoacoustic gas sensing silicon microsystem has been patented anddeveloped by 54.7, as well as numerous refrigerant gas leak detectorsthat are commercially available from a variety of manufacturersincluding Yokogawa and Stonegate Instruments. The refrigerant will mixwith air and may be detected by a halogen gas detector, however if theleak is very small, and air there is significant air flow near the leak,typically no signal (detection) by the gas leak detector will be given.The advantage of combining the gas leak detector with the UV/Blue lightsource is that of combining general air detection and that of highlylocalized dye marks. Thus by first localizing the leak area with thehalogen gas detector, the area to UV/Blue light source can be uses tosearch the immediate area to pinpoint the leak (which may not bedirectly visible).

[0014] The present invention, hand held flexible mount leak detector,addresses a particular need for detecting refrigerant leaks from asystem that has environmental access restrictions and requires specificdetection methods. Referring to FIG. 2 in conjunction with FIGS. 3a, 3b, 3 c and 3 d, there is shown one embodiment of the present invention,hand held flexible mount leak detector 200. The flexible mount leakdetector consists of a main body 202, flexible stalk 204 and a sensorprobe head 206. In one embodiment of the present invention, the sensorprobe head 206 contains a UV/Blue LED light source 208 and a halogensensor access port or halogen sensor 210. The main body 202 provides forhand held portability and provides the electrical power for the UV/BlueLED source 208 and the interface. The flexible stalk 204 provides fixedmultiple positions of sensor head and a conduit for electrical powerrequired by remote mount sensors. The flexible stalk 204 also providespneumatic conveyance required by sensor probe head 206. Sensor probehead 206 is connected to main body 202 by the flexible stalk 204. Theshape of the main body 202 is adapted to be easily held and allow thedevice to be simply operated with a single hand, enabling the UV/BlueLED light source 208 to be quickly activated and deactivated and thehalogen gas detector to be controlled. In yet a further embodiment aswitch 212, such as a momentary action switch, is mounted in the mainbody 202, enabling easy single hand operation which provides eyeprotection from UV emissions, my making the UV emissions available ondemand, when maneuvering in the confined quarters that the operatortypically must work in.

[0015] The flexible stalk 204 can be made from a variety of materialsknown to those skilled in the art, including but not limited to metal,plastic, rubberized materials, as well as flexible tubing having aninner bendable member (wire, etc.) or an integral bendable member withinthe tubing wall. In a further embodiment, the flexible stalk 204, sensorprobe head 206 and main body 202 are made from or covered in anon-conducting material, such as plastic, rubberized materials, etc.providing safety by eliminating the potential danger of causing anelectrical short circuit, which can easily happen in an environment suchas an automobile engine compartment or the passenger compartment areabehind the dash board. The shape of the flexible stalk 204 can bechanged easily, including during single hand use by holding the mainbody 202 in the hand and pressing the flexible stalk 204 against therefrigeration system fittings, tubing, and other structures as well.Thus providing a rapid system for detecting a refrigerant leak inconfined quarters, where access by a probe as well as for the operatedof the probe is restricted.

[0016] The UV/Blue LED light source 208 (which as previously describedmay be multiple LEDs) is mounted in sensor probe head 206 with powersupply mounted in the body 202 or alternatively with the power supplymounted in the sensor probe head 206. The gas detector 210 maybe asensing device mounted in sensor probe head 206 with electroniccircuitry mounted in sensor probe head 206 or main body 202.

[0017] The UV/Blue LED source 208 requires very little power enablingthe use of a small and portable battery device. A separate lens to passUV/Blue light is not required as the LED typically generates energy inthe UV/Blue region saving cost, weight, and cost.

[0018] General advantages of the combination leak detector include aflexible stalk having a UV/Blue LED source 208 and gas detector sensor210 and its single hand operation. The UV/Blue LED source 208 generatesalmost no heat in contrast to traditional most UV/Blue light sourcesthat generate large amounts of heat requiring turning light off afterapproximately 3 minutes of use and cooling off for a period of timebefore using again. The UV/Blue LED source 208 is small enabling accessto areas that maybe a problem with traditional UV/Blue sources. Thenarrow frequency range of emissions by the UV/Blue LED light source 208does not require filters to excite fluorescent dye.

[0019] Halogen leaks can respond to dye leak checks or gas detectionleak checks. Some leaks only respond to one or the other. Having bothdye and gas detection in the same probe provides an advantage indetecting leaks and pin pointing their location.

[0020] Numerous modifications and alternative embodiments of theinvention will be apparent to those skilled in the art in view of theforegoing description. Accordingly, this description is to be construedas illustrative only and is for the purpose of teaching those skilled inthe art the best mode of carrying out the invention. Details of thestructure may be varied substantially without departing from the spiritof the invention and the exclusive use of all modifications, which comewithin the scope of the appended claims, is reserved.

What is claimed:
 1. A hand held refrigeration leak detector comprising:a main body; a flexible stalk coupled to the main body; a head coupledto the flexible stalk; and an LED light source mounted in the head. 2.The hand held detector as recited in claim 1 wherein the LED lightsource has a spectral emission in the UV range.
 3. The hand helddetector as recited in claim 1 wherein the LED light source has aspectral emission in the UV to blue range.
 4. The hand held detector asrecited in claim 1 wherein the LED light source is comprised of at leasttwo LEDs.
 5. The hand held detector as recited in claim 1 furthercomprising a gas detector.
 6. The hand held detector as recited in claim5 wherein the gas detector is an integrated gas sensor mounted in thehead.
 7. The hand held detector as recited in claim 5 wherein the gasdetector has a gas sensor port mounted in the head.
 8. The hand helddetector as recited in claim 1 wherein the main body is adapted tocontain a power supply.
 9. The hand held detector as recited in claim 1wherein the head is adapted to contain a power supply.
 10. The hand helddetector as recited in claim 1 wherein the main body further comprises aswitch for activating the LED light source.
 11. The hand held detectoras recited in claim 10 wherein the switch is a momentary action switch.12. The hand held detector as recited in claim 1 wherein the flexiblestalk is covered in a non-conducting material.
 13. The hand helddetector as recited in claim 1 wherein the flexible stalk is made from anon-conducting material.
 14. The hand held detector as recited in claim1 wherein the head is covered in a non-conducting material.
 15. The handheld detector as recited in claim 1 wherein the head is made from anon-conducting material.
 16. The hand held detector as recited in claim5 wherein the main body further comprises a switch for activating thegas detector.
 17. The hand held detector as recited in claim 5 whereinthe gas detector is a halogen gas detector.
 18. The hand held detectoras recited in claim 10 wherein the switch for activating the LED lightsource is adapted to be actuated by while holding the main body of thedetector with a single hand.
 19. The hand held detector as recited inclaim 16 wherein the switch for activating the gas detector is adaptedto be actuated by while holding the main body of the detector with asingle hand.
 20. The hand held detector as recited in claim 1 whereinthe main body is covered in a non-conducting material.
 21. The hand helddetector as recited in claim 1 wherein the main body is made from anon-conducting material.
 22. The hand held detector as recited in claim8 wherein the power supply is a battery source.
 23. The hand helddetector as recited in claim 9 wherein the power supply is a batterysource.